Brake drum



Sept. 19, 1933. J AMPBELL 1,927,305

BRAKE DRUM Filed May 18, 1931 2 Sheets-Shgep l Women s Q Sept. 19, 1933. D. J. CAMPBELL 1,927,305

BRAKE DRUM Filed May 18, 1931 2 Sheets-Sheet 2 f? {noun Yo) l5 Dona dfnm flm Patented Sept. 19, 1933 UNITED STATES PATENT OFFKIE 4 Claims.

This invention relates to brake drums, and is particularly concerned with a novel construction of brake drum, wherein a pressed metal shell is lined at its inner curved side with a continuous band of cast iron or other suitable metal, is equipped with means through which the heat generated when a brake frictionally engages against the inner side of the cast metal band is very quickly and rapidly dissipated, and there is not produced undue strains between the inner cast band and the outer pressed metal drum which may otherwise occur because of the heating of said band and its expansion with greater rapidity than the drum shell which surrounds it.

It is an object and purpose of the present invention to provide a novel construction of heat dissipating brake drum wherein the heat generated in service is taken care of and quickly and rapidly dissipated. More specifically, the invention is concerned with a novel means of quickly and rapidly carrying heat from the inner cast bandto outer annular projecting vanes either integral with or secured in any suitable manner to and around the outer drum shell, said wings or vanes serving also as a strong strengthening and reinforcing element around the brake drum to maintain it against distortion or other undesired change of shape. The invention may be understood from the following description, taken in connection with the accompanying drawings, in which,

Fig. 1 is an elevation of one form of the drum in accordance with my invention, parts of the same being broken away and shown in section for a better disclosure of the construction.

Fig. 2 is a fragmentary enlarged transverse section, substantially on theplane of line 2-2 of Fig. l.

Figs. 3 and 4 are sections similar to that shown in Fig. 2 of slightly different forms of construction embodying the invention. a

Fig. v5 is an elevation, partly in section, like that shown in Fig. 1, of a still further form of construction of brake drum embodying my invention. I

Fig. 6 is an enlarged transverse section on the plane of line 6-6 of Fig. 5.

Fig. 7 is a fragmentary vertical section substantially on the plane of line 7-7 of Fig. 6.

Fig. 8 is an edge view of the central outwardly projecting rib or vane on the drum construction shown in Figs. 5 and 6, and

Fig. 9 is an elevation'of one of the heat dissipating members interposed between the outer drum shell and the inner band in the construc-. tion shown in Figs. 5 to 8, inclusive.

Like reference characters refer to like parts in the different figures of the drawings.

The brake drum shown in Figs. 1 to 4 inclusive includes a circular web 1 from which an annular flange 2 is pressed at right angles, terminating in an outwardly extending annular flange 3; though so far as invention is concerned, this flange 3 may be replaced by an inturned lip as is used in some forms of drum construction.

Within the drum, which is of pressed metal,

and against the inner side of the annular flange 2, is a continuous band 4 preferably of cast iron which may be applied in any suitable manner. The manner in which it is applied by the is fully set forth in my prior application, Ser. No. 512,792, flled Feb. 2nd, 1931, for centrifugal casting.

At the outer side of and around the annular flange 2 of the drum a continuous channel ring of metal is located, the web 5 of which is in direct intimate contact with the outer side of the flange 2, while the flanges 6 of the annular channel member extend outward in substantially parallel relation to each other. A large number of rivets 7 in spaced relation to each other are located around the drum with their heads between the band 4 and the flange 2 of the drum and their shanks extending through openings in the flange 2 and through the web 5 of the channel ring; and as shown in Fig. 2, the outer ends of the rivets may be headed over, as indicated at s. These rivets are of copper or aluminum or any other metal of similar high heat conductivity. In practice, copper rivets preferably are used.

In Fig. 3 the construction is the same except that the shanks of the rivets extend directly outward through the web 5 of the annular channel .ring and are not up set and headed over at their outer ends. In Fig. 4 instead of using the rivets 7 a plurality of openings are drilled through the web 5 and the flange 2 of the at9.

In all of these forms of construction, heat which is generated by the friction of brakes bearing against the inner band 4 of the drum is first absorbed by said band 4 and, therefrom, is carried very rapidly outward by the conduction ties provided by the rivets 7, in the structure shown in Figs. 2 and.3, while in that of Fig. 4 it is carried outwardly through the openings 9. The outwardly extending flanges 6 of the annular channel rings serve as fins or vanes and heat herein is' very quickly dissipated and the nns cooled by their large contact surfaces with the drum as indicated air. In Figs. 2 and 3 the heat conducted by the rivets '7 is conducted directly to the annular channel ring members and either of these constructions, such as shown in Figs. 2 and 3, is preferred to that shown in Fig. 4 because of greater emciency in heat dissipation.

In Figs. 5 to 9 inclusive a different form of construction embodying the invention is shown. The outer shell of the brake drum consists of two parts both of pressed metal. One part has a circular web 10 from which a flange 11 is pressed substantially at right angles, terminating in an outwardly extending annular flange 12 substantially at the middle of the drum. Associated with this is the second brake drum member, which is a. ring having an outwardly extending flange 13 lying in direct contact engagement with the flange l2 and securely welded thereto, from which a section or flange 14 extends at right angles in substantially the sameplane with the part 11, and which terminates in an inturned (annular lip 15 as best shown in Fig. 6. The

flanges 12 and 13 are welded together around their entire peripheries and a substantially integral construction made. a

Heat conducting elements are provided of copper rod bent into L-shape form, and having two legs 16 andl7 at right angles to each other. The legs 16 lie in the inner groove formed where the two: flanges 12 and 13 come together and the legs 1'7 extend, radially outward through suitable openings to the outer edges of said flanges 12, 13 as shown. Within the drumand completely eoveringthe legs 16 is a cast metal band 18.

-With this construction the heat generated and which is absorbed by the band 18 is conducted by the L-shaped heat conducting members to the outwardly extending annular flanged ring at the outer side of the drum, made by the welding together of the two flanges l2 and 13, and the heat is very rapidly dissipated as is evident.

.- The annular channel member around the outer sides of the brake drum, as shown in Figs. 1 to 4, inclusive, in addition to providing heat dissiflanges 12 and 13 together strengthens and reinforces the drum construction shown in Figs. 5

to 9 inclusive.

The construction described has proved very practical in service and insures against quick or over heating of the brake drum and its too great expansion and/or contraction which, by reason of the bimetallic character of the drum, is to be guarded against as much as possible.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. A brake drum comprising, an outer shell of pressed metal having a continuous annular flange, a brake band of cast iron within said flange, a plurality of spaced apart rivets having the heads thereof located between the inner side of the flange and said band, the shanks of the rivets passing through the flange, and an annular outwardly extending rib around said flange with which the shanks of said rivets have heat conducting connection.

2. A brake band comprising, an outer shell of pressed metal having a continuous annular flange, a band of cast iron within said flange, a ring of channel cross section located around and at the outer side of said flange having the legs thereof extending outwardly and spaced apart and heat conducting members extending through the flange and joining said band and channel ring in heat conducting relation to each other.

3. In a brake drum, an outer shell having an annular flange section and an annular projecting rib at the outside of and around said flange section, a band of metal of difierent character than the shell located around, within and in intimate contact with the inner side of said flange section, and a plurality of heat conducting members between said band and flange section having parts extending outward through said rib between the opposed sides thereof.

4. A brake drum comprising, an outer shell having a substantially vertical web and an annular continuous flange section extending substantially at right angles .to the web, said flange section between its opposite edges having a continuous outwardly extending annular rib, a band of cast metalat the inner side of and in intimate contact engagement with said flange section, and a plurality of L-shaped members having legs located at right angles to each other disposed with one of said legs of each member between the band and said flange section and the other leg extending outwardly through said rib.

DONALD J. CAMPBELL. 

